The present invention relates to information retrieval, and in particular, information retrieval using a hybrid spoken and graphical user interface. Various problems regarding information retrieval and user interfaces are described below. It is to be understood that some of these problems may seem unrelated without having the benefit of this disclosure.
One problem relating to information retrieval is that relatively inexpensive storage has enabled people to assemble large personal collections of non-traditional documents, such as music files, movies, pictures, or other media files. This presents a particularly challenging information retrieval problem because these collections are becoming more portable. Traditional information retrieval interfaces that rely on full sized keyboards are impractical or undesirable in some environments. Further, the time value of such information approaches zero. That is, if the search process requires more than a moment to retrieve a picture, a song, or a movie, then it may not be worth the search time for casual enjoyment purposes. Therefore an improved user interface is desirable.
There are also problems with the use of classic information retrieval systems. Most information retrieval systems attempt to follow the probability ranking principle, which asserts that optimal retrieval is when documents are retrieved in order of the probability of relevance. This is true even for systems that are not themselves probabilistic. Google is such a system. Yet, such a system does not adequately consider the possibility that in some instances the documents may be equally relevant and where the documents are equally relevant there may be some particular order which should be used to organize the results. Similarly, consider a set of queries for which nearly all documents have a score of zero. Such a system does not consider the problems with ordering. If the same zero scoring documents always appear towards the top of the list, then at best some opportunity for serendipity is lost and at worst those irrelevant documents become a source of irritation. Such problems do not necessarily happen very often with verbose documents such as journal articles and web pages. However such problems are particularly likely to occur with documents having only brief descriptions.
Another problem with user interfaces is that associated with portable or embedded devices. Such devices tend to rely almost exclusively on menus rather than queries for searching. This works well only for very small collections. Most innovation is focused on tactile mechanisms for moving through menus. The iPod wheel is one such example of this.
There are also problems with using speech recognition in user interfaces. Speech recognition has yet to enjoy great success in user interfaces. Users have difficulty learning what they can say. Grammar based systems are particularly difficult. Human beings, unlike computers, are not good at looking at context free grammar rules and constructing valid sentences. Accuracy is often a problem. Another problem with using speech recognition in a user interface of a portable or embedded device is that speech recognition may require significant processing, memory, or other requirements which are otherwise unnecessary for the device.
Therefore, despite various advances, problems remain with providing user interfaces for information retrieval.